Embodiments in accordance with the present invention relate to a magnetic head for perpendicular recording, a magnetic disk storage apparatus mounting the head, and a manufacturing method of a magnetic head.
A magnetic disk storage apparatus includes a recording medium and a magnetic head, and data on the recording medium are read/written by the magnetic head. It is desirable to reduce a recorded bit for improving the recording capacity per unit area of the magnetic recording medium. However, in a current longitudinal recording method, there is the problem that the recording density cannot be increased because the issue of the thermal fluctuation of the magnetization of the medium arises when the recording bit length becomes smaller. A solution to this problem is a perpendicular recording method, in which the magnetization signal is recorded in the direction perpendicular to the medium. There are two kinds of perpendicular recording methods; one is a method using a double-layer perpendicular medium which includes a soft under layer as the recording medium and another is a method using a single-layer perpendicular medium which does not include a soft under layer. In the case when the double-layer perpendicular medium is used as the recording medium, a larger write-field can be applied thereto when writing is performed by using a so-called single-pole-type writer which includes a main pole and an auxiliary pole. Considering the case where the head has a skew angle, it is assumed that the shape of the air bearing surface of the main pole is a trapezoidal shape where the width at the leading side is narrower.
Moreover, the field gradient in the perpendicular element profile of the head field which writes the transition of the write bit cell, that is, the field gradient of the head field in the head downtrack direction is an important factor to achieve a high recording density in addition to the write head field intensity. The field gradient has to be increased further to achieve a higher recording density in the future. A structure where a magnetic material is arranged at the trailing side of the main pole is known to improve the write-field gradient. Moreover, a structure where a magnetic material is arranged at the side of the main pole is also known.
Generally, a magnetic head is manufactured by stacking magnetic films, in order, on a substrate by using a sputtering technique or a plating technique. Therefore, a conventional structure is one where the face at the leading side of the main pole is parallel to the substrate and perpendicular to the head air bearing surface.